The free stuff is nice, but they don't offer thousands of title for free. It is more like several dozens. The TV shows and movies cost a small fortune each to rent or own, and quite frankly it isn't worth what they charge. I already had Amazon Prime to save on shipping costs otherwise I wouldn't have it just for the videos. Netflix is a much better deal.

I don't watch a lot of videos and like you I primarily use Prime for the 2 day shipping which is awesome.

However, according to Amazon's website under my Prime Membership:

You have unlimited instant streaming of over 10,000 movies and TV shows, included with your Amazon Prime membership at no additional cost. Start watching now.